Non-Clog Self-Priming Sewage Pump for Rain Water 5'' Size

They can handle a variety of liquids including slurries and corrosive fluids. Unlike submersible pumps, they continue to pump even when not submerged. They are ideal for frequent and intermittent operations as priming steps are eliminated.

They require initial priming liquid in the reservoir. Due to the reservoir, they may be larger than standard models, causing space issues. They need to be close to production lines to avoid depleting the liquid reservoir during self-priming.

In principle, all positive displacement pumps are self-priming, including rotary gear, lobe, vane, and diaphragm pumps. However, dry running can cause overheating and seal wear. It is important to consult the manufacturer before using them in applications requiring self-priming and dry running.

Standard centrifugal pumps are not self-priming as they cannot evacuate air from a suction line when the liquid level is below the impeller. However, with modifications to surround the impeller and volute with a liquid reservoir, they can become self-priming. They still require liquid in the housing to start.

Common reasons include air leaks in the suction line, debris plugging the impeller eye, the pump being air-bound due to closed valves or lack of air release line, excessive impeller clearance, or a plugged recirculation port. Undersized pumps may also fail to create the necessary low-pressure area.